Loom let-off mechanism



Nov. 30,1926.: 1,608,834

J. W. BOOTH ET AL Y l LOOM LET-OFF MEGHMIISM4 Patented Nov. 30, 1926.

Ltii PATNT OFFICE.

JAMES WILLIAM BOOTH AND THOMAS CRAVN contines, or KEIGHLEY, ENGLAND.

Looivr tenori@ Mechanism.

Appncation inea 'February 23, 192e, serial No. eases, and ai creat Britain February ae, 1925.

This invention relates to loom left-oft mechanism of the type or class wherein the retarding actions upon the warp beain are effected by chains, ropes, clamps or other brake devices and which actions are gradually reduced in accordance with the diminishing diameter of the coils of warp on the warp beam.` Our presentinvention consists in a novel construction and arrangement of the devices which connect the detector meinber to the moving weiofht on 'the lever which effects or brings abortil the brake action, by which the whole mechanism may be readily fixed in position, will occupy'comparatively little space and will act with eflicient regularity.

In order' that our said invention may be readily understood, we have hereunto appended a sheet of drawings illustrative thereof, to which by figures and letters, reference is made in the following description. Fig. 1 is a rear view of sufficient of a loom to show the application of our devices to the warp beam in connection withsaid loom.

Fig'. 2 is a plahof the parts shown by Fig. 1 'with a portion of the warp beam cut away so that the parts beneath might be more clearlyseen.

Fig. S is a similar view to 1 and shows cerain of onr parts drawn to an enlarged sca e.

Fig. t is an end elevation of parts shown by Fig. 3 as seen in the direction looking from right to left of said figure. I

Fig'. `5 is a similar view to Fig'. 3 but illustrates a modification hereinafter explained.

A indicates the end frame of the loom B, B1 the upper' and lower back rails of said loorn and C the'warp beam. i

In carrying oni"1 invention into effect we make nse of a' bell crank lever 2 which we arrange to have one arm a' to carry a weight 3 while the other arm b extendsvertically preferably in a downward direction as shown by the drawings, so thatit may be' coupled by any suitable `conne'ations as the ro'd 4i", the chain il, connecting rod 5, `guide pulley and connectin' rod 6,to levers 7, 7a, e and se which latter are `pivoted at fl, (Z1 and operate' in well known manner in connection with this type of let-,olf mechanism' by said levers 8, 8a actuating' the brake blocks 9, 9i which' partly encircle the outer ends of the beams C as is well known or which might meats chains. c

The weight 3 carried by the arm a of the i,the detector rollers 10 which are mounted to revolve on bearingskat the upper end of a sliding bar or rack 11 according` to the alternative Yariangernents of our `invention as illustrated by Fig. 1 and Fig. 5, the alternative arrangement in Fig. 5 being hereinafter described. c v

The vertical bar 11 according to the arrangement-shown by Figs. 1 to 4 is in the Aforni of ar rack the teeth of which 'mesh with acpinioii 12 pivoted onthe shaft g moiinted upon the bearings 13 which are `supported by a separate bracket 111 that will slide over a bracket 15 fixed to the lower rail B1 at the rearof the loom. The adjustment of the bracket 13 by hie-ans of sliding the bracket 14 upon the bracket 15 is to securethe fulcrtiin f of the lever 2 in siich a position as to keep the arm `a of said lever practically hori- Zontal throughout all the letting-off operations. N y

It will be observed that the parts supported by the fixing brackets 15, 14, and 13 may all be assembled on said brackets prior to being `fined np'on the loom so that when thus assembledthe whole may be mounted in position by iixingthe bracket 15 to the rail B1.

.Upon the short shaft g forming the support fortlie" pinion 12 is fixed another pinion 16 `which,engages with `the teeth of a rack 17 that slides horizontally upon the bearings 18 as such rack 17 is moved 'under the recoil of the spring 19 which at all tinies tends to cause said rack 17' to inoveyin the direction indicated by the arrow m. This is enacted by the end of the spring near the shaft gbeing' fined to thebearing 13 while the other end of thespring 19 is fixed to the end of the rackl. As the coils of warp on the beam C decrease indiameter the pull of the spring 19 causes thepifnionsI 16 and 12 to revolve and thereby raise the rack bar l1 so as to force the detector rollers 10 against the snrface of the beam C, and during such rising;r movement of the rack bar 11 the rack 17 will have move as is stated in the direction in dicated by the arrow and will bybeing connected with the rod 20 to the weight 3 move said weight along the arm a of the lever 2 causing same to travel nearer to the ulcrum f of said lever and thereby to gradually decrease the power that said weight has over the said lever 2 and consequently to decrease its power over the friction b-rakes 9 and 9a.

The arm b of the lever 2 has mounted on it a vertical screw 21 which supports or carries the end of the connecting rod la closer to or further from the fulcrum f as the nature of the work or the power required to be exerted by the weight 3 over the brakes 9 and 9L may demand, the further the connections Ll, 4a upon said arm b of the lever 2 are from the fulcrum f so will the force exerted by the lever 3 be less over the brakeshoes 9 and 9a.

The arrangement of our devices as' above described enable us to mount same in sucha position that the detector rollers 10 may be practically vertically beneath the centre of rotation of the beam C while'the mounting of the lever 2 and the other devices in connection therewith fall within the outer diameter of the same beam C consequently the mounting of our devices in position upon vthe loom does not interfere with the useful space or gait between said loom and the one to the rear of same which has advantages for many and varied purposes.

As an alternative to the employment of the racks 11 and 17 we may make use of a bar 11d (shown by Fig. 5) for supporting the detector rollers 10 and this bar we may arrange to be hollow so that a chain 22 fixed to the outer end of the sliding bar 23, which we use in place of the rack 17, may take over a guide pulley or other device in order that its outer end may be fixed to the lower end 7c of the bar 11a. This sliding bar 23 is ac tuated by the spring 19 as is the rack 17 so that by the spring 19 being fixed at m to the bracket 13 while its other end is fixed to theend of the bar 22 said spring is enabled to raise by its recoil the bar ,11a as will be understood. During the horizontal movement of the bar 23 it will carry with it the connecting rod 20 which connects it to the weight 3 as is the case in our other arrangement.

Such being the nature and object of our said invention what we claim is 1. ln loom let-off mechanism, a detector for contacting with the warp on the warp beam, a vertically extending barupon which said detector is mounted, means for connecting said vertically moving bar to a horizontally moving bar so that the one may be operated by the other, a spring attached to the horizontally moving' bar and to a bracket which supports the said horizontally and vertically moving bars, a lever pivoted upon the same bracket and arranged to receive a weight,'said weightformed to slide" over said lever, means for coupling the weight to the horizontally sliding bar, means for coupling the weighted lever to levers which actuate the brake applying devices to the warp beam and said warp beam.

l'n loom let-olf mechanism, a detector for contacting with thel warp on the warp beam, a vertically extending bar upon which said detector is mounted, said bar having rack teeth formed upon it, a toothed pinion engaging said rack teeth, another toothed pinion fixed to the former, a horizontally moving rack bar engaging with the second pinion, a supporting bracket upon which said rack bars and pinion are mounted to operate, a spring connected to the horizontally moving rack bar and to the bracket, a connection from the horizontally moving rack bar to a sliding weight, saidvsliding weight, a lever upon which said weight is arranged to slide, said lever being mounted upon the bracket which supports the verti` cally and horizontally moving rack bars and and toothednpinions, a connection from the weighted lever to levers which actuate Lthe brake applying devices on the warp beam, said brake applying devices and said Warp beam.

3. ln loom letoflk mechanism, a detector for contacting with the warp on the warp beam, a. vertically sliding bar supporting said detector, a horizontally sliding bar, means for connecting said horizontally slid-A ing bar to the vertically sliding bar so that when the horizontal bar is moved so is also the vertical bar, a spring for actuating the horizontal bar, a supporting bracket to which said spring is attached, said bracket also supporting the vertically and horizontally moving bars, a weighted lever connected to the horizontally moving bar so that it is caused to slide over the arm of a lever, said lever, a connection from said lever to levers which apply braking actions to the warp beam and means for regulating the point of attachment of the connection to the weighted lever so that .its leverage mayy be altered and adjusted.

4. ln loom let-olf mechanism, a detector, a sliding bar carrying said detector, a horizontally moving bar connected to move in unison with the detector moving bar, means for supporting said bars, means for connecting one bar to the other, a spring for operating said bars, connections from said bars to a sliding weight, said sliding Weight, a lever upon the arm of which the sliding weight acts, flexible connections from said lever taking around a guide pulley mounted on levers at one end of the loom so that a connection therefrom may be coupled to the levers at the other end of the loom, said connection, said two sets of levers; brake mechanism operated by said two Sets of levers-so as to retard the rotary motions of the warp beam and said warp beam.

5. In loom let-olf mechanism, a detector for contacting with the Warp on the warp beam, vertically and horizontally moving rods, the former beingr arranged to support the detector While the latter is arranged to transmit motion to the former, means for connecting the two sliding bars together, a spring,` connected to the horizontally moving bar and to a fixed bracket, said fixed bracket, lever mounted upon said fixed bracket and a Weight mounted to slide upon said lever,

means for connecting said Weight to the hori- Zontally sliding bar7 screw actuated adjusted means for moving` and regulating the point of contact of the connection to the Weighted lever, means for coupling said adjustable connection on the Weighted lever to other levers for actuating brake mechanism, said brake mechanism mounted in conjunction with the Warp beam and said Warp beam.

JAMES VILLIAM BOOTH.

THOMAS ORAVEN OORLASS. 

